Computer communication networks have become the de facto method of communication for the modern world. In addition to communication between private citizens, various organizations use computer communication networks to communicate, share information, and share documents. Much of this communication is transmitted over non-private computer networks (such as the Internet).
Organizations, such as corporations and governments, often need to communicate sensitive information over the Internet. As such, being able to securely transmit the information over the Internet is very important. Some organizations use encryption techniques to attempt to secure information crossing the Internet unreadable to non-authorized parties. Some organizations use virtual private networks (VPNs) to secure their computers and system.
Additionally, large organizations typically desire to make data and services available to users who are located remotely from the computer systems that store the data and provide the services. However, by making these resources available over a public network also makes them more vulnerable to a malicious attack.